A haemorrhoidectomy (removal of the engorged vein around the anus) may 'cure' haemorrhoids, but it may also be the cause of even more painful problems.
Researchers studying 22 patients who underwent a procedure known as stapled haemorrhoidectomy found that persistent severe pain and faecal urgency were side effects in a "disturbingly high" proportion of patients.
In all, 31 per cent of the individuals studied had pain and faecal urgency which persisted for up to 15 months after their operations.
The results were so evident that the randomised trial was suspended so that doctors could investigate what went wrong.
In four out of five cases, no medical reason other than the haemorrhoidectomy could be found (Lancet, 2000; 356: 730-3).